#linkid rt_coroutine_new
fn coroutine_new(anyptr function, int flag, anyptr future):anyptr

#linkid rt_coroutine_async
fn coroutine_async(anyptr function, int flag, anyptr future):anyptr

#linkid rt_coroutine_dispatch
fn coroutine_dispatch(anyptr co)

#linkid rt_coroutine_return
fn coroutine_return(anyptr result)

#linkid rt_coroutine_await
fn coroutine_await(anyptr co)